A building and a structural cassette for the building

Abstract

A structural cassette comprises a profiled steel deck (1) having a generally planar base layer from which a plurality of raised profiles (3) extend on one side. The profiles extend for the full length of the cassette. A thermal storage layer (2, 80) is formed on the one side of the profiled steel deck. A sheet (4) is fitted below the profiled steel deck to form a plurality of air passages (5) between the sheet and the raised profiles. Air inlet and outlet ducts (3) at the ends of the cassette communicate with the air passages (5). The cassette may be used for floor, wall and ceiling panels and air may be selectively directed between them.

Description

[0001] A BUILDING AND A STRUCTURAL CASSETTE FOR THE BUILDING

[0002] The present invention relates to a building and a structural cassette for a building.

[0003] In particular, it relates to the heating or cooling system for a building.

[0004] There are several known ways of heating buildings. In individual residences, central heating systems distribute heated water to a system of radiators, or individual heaters are provided in each room. In larger buildings, the heating system usually takes the form of a system of ducts which extend around the building and supply hot air to individual rooms, usually through the ceiling tiles. These systems are usually also used to provide air conditioning.

[0005] Underfloor heating is also known in which electrical heating elements or ducts to convey hot water are installed beneath the flooring. Underfloor heating is relatively expensive and is generally only used in higher end of buildings, or to provide heat to a relatively small area.

[0006] The present invention aims to provide a heating and / or cooling system for a building which can be implemented at low cost and is economic to operate.

[0007] According to a first aspect of the present invention, it is provided a structural cassette according to claim 1 .

[0008] The present invention is based on a modification to a well-known profiled steel deck following the realisation that this can be adapted by the application of a sheet to form closed passages which can be used to convey air along the profiled steel deck.

[0009] Such an arrangement provides a very simple way of adapting existing, well established building technology to provide a heating and / or cooling system. For simplicity, reference will be made below to heating. However, it will be appreciated that an analogous effect can be achieved for cooling using airstream which has been cooled. As it uses hot air, this is available cheaply and easily as it does not require a separate plumbed circuit which is prone to leaking and freezing. Also, the air used in the present invention is benign in the event of a leak.

[0010] As the hot air travels through the building structure, any heat lost from in transit is lost or absorbed into the materials with good thermal storage capacity into the building thereby improving overall thermal efficiency.

[0011] Air based systems are well able to take advantage of the increase of low / neutral carbon heat sources such as solar heating and ground sourced hot air.

[0012] The thermal storage layer allows the heat distributed through the air circulation system to be stored in the short term. This allows flexibility within the heating system as it can be operated when a source of power is readily available or is available more cheaply and the thermal storage layer will allow the heat to be released into the building over the longer term. The system is therefore well adapted to a more intermittent energy supply such as that available from renewable resources as it can take advantage of the power when it is available because of over generation. It is therefore more environmentally friendly and also more cost effective. In warm countries, the system can be run at night to cool the thermal storage layer which will help maintain a low temperature during the day.

[0013] The combination of the thermal storage layer and the heated air in the air passages provides good insulation as the air is also a good insulator. Again this improves the overall thermal efficiency of the building as the temperature of the thermal air can be controlled to maximise the efficacy as an insulator.

[0014] The panels may form the floor, wall and / or ceiling / roof panels or any combination of these. In this case, air passages from the various panels may be connected together to form an air circulation system. However, preferably, the panel is a floor panel. This is where the profiled steel decks are most commonly used. Further, in this case, the air passages run below the floor of the building thereby providing underfloor heating to the rooms within the building. This is more efficient than providing heat with ceiling tiles as the heat naturally rises up through the room.

[0015] A bonus effect provided by the invention is that the presence of the sheet fitted to the profiled steel deck means that each of the open channels on a conventional profiled steel deck now effectively has a box beam construction. This significantly enhances the rigidity of the panel which is particularly beneficial in a floor or ceiling panel as the span of the panel can be increased along with the load bearing capacity.

[0016] The heating and / or cooling unit may be any heating and / or cooling unit. However, probably it is a zero / low carbon unit such as a heat pump or solar heating system.

[0017] The thermal storage layer may be any suitable layer which can store a reasonable amount of heat. Preferably it is a cementitious material such as concrete or a cement particle board. Cement particle board is particularly applicable for floor, wall and ceiling / roof panels. Using a board means that the gaps between the raised profiles can, with the board, form auxiliary passages in addition to the air passages within the raised profiles. These can be filled with insulation or left open to provide auxiliary air passages to allow for increased air flow through the panel if needed.

[0018] The thermal storage layer preferably has a thermal storage capacity of greater than 600 J / kg°C, more preferably greater than 700 J / kg°C and most preferably greater than 800 J / kg°C. Concrete has a thermal capacity of 880 J / kg°C.

[0019] The air circulation system is preferably further provided with a heat recovery system from the air leaving at the air outlet duct. This is achieved by the heat from heated air being recovered at a heat exchange plate or being recirculated via a thermostatic valve to recover as much heat as possible for recirculating air in the ducts.

[0020] The cassette is able to be formed in a controlled factory setting. This avoids atmospheric problems such as temperature fluctuations, humidity and freezing. This provides a considerably reduced time and cost on site as compared to conventional methods. Another advantage of factory forming, is the deck is fully supported in the factory negating the need and cost for propping the underside whilst cementitious materials are being poured and setting, which takes several days to cure. Further, as mentioned above, the presence of the sheet below the profiled steel deck forms closed beam sections which enable the span of the cassette to be significantly increased.

[0021] The cassette is preferably formed such that the profiled steel deck and thermal storage layer are a self-supporting structural component. More preferably, a non-load bearing element is attached beneath the sheet. Such a cassette is disclosed in earlier W02022 / 090076.

[0022] The non-load bearing component may, for example, provide support for services and / or insulation. A number of other features may be included in that the cassette such as a weld mesh embedded in the concrete layer, a layer of insulating board above the concrete layer, ceiling panels and services including electrical cables and pipe work. Further details of these are provided in W02022 / 090076.

[0023] In W02022 / 090076, a plurality of joists or suspension system are attached to the lower face of the structural cassette to provide support for various items fixed below the profiled steel deck. In the present cassette, a beam structure is preferably attached to the underside of the cassette in order to provide at least one joist on its lower face. The beam structure may be formed integrally with the sheet but is preferably a separate structure fixed to the sheet.

[0024] The or each beam structure may form a single channel. However, preferably, the or each beam structure forms at least two channels. This provides greater opportunity for the fixing of components to the underside of a cassette. For example, one of the channels may support a slab of insulation and the other can provide support for the services.

[0025] Preferably the beam structure is provided with through holes. This allows services to pass through, rather than just along the beam.

[0026] The or each beam may run parallel to or transverse to the raised profiles of the steel deck.

[0027] Concrete may be poured directly onto the steel deck. Alternatively, a top sandwich panel may be placed on top of the steel deck. Concrete can be poured onto the sandwich panel, but, in this case, a cement particle board may instead be installed on the sandwich panel.

[0028] In this case, the gap under the sandwich panel and the steel deck can be provided with insulation.

[0029] The profiled steel deck has preferably has a trapezoidal profile in which the air passages are wider at the side closest to the sheet. The profiled steel deck is preferably fixed to the sheet by chemical bonding, mechanical fixing, and / or spot welding. According to a second aspect of the invention, there is a building comprising a framework which supports a plurality of floor, wall and / or ceiling / roof panels; at least one of the panels comprising: a structural cassette according to the first aspect of the invention; an air circulation system for circulation of heated and / or cooled air to the inlet duct and from the outlet duct; and a heating and / or cooling unit to heat and / or cool air for the air circulation unit.

[0030] The air circulation system is preferably provided with a heat recovery system from the air leaving at the air outlet duct.

[0031] The air circulation system preferably comprises a thermostatically-operated valve to recycle air from the outlet duct back to the heating / cooling unit.

[0032] The air circulation system preferably comprises a mechanical ventilation heat exchanger.

[0033] The air circulation system preferably comprises a valve system and a control system to selectively circulate heated and / or cooled air to the floor, wall and / or ceiling / roof panels.

[0034] An example of a building and a structural cassette in accordance with the present invention will now be described as reference to the accompanying drawings, in which:

[0035] Fig. 1 is a cross sectional view through a pair of cassettes positioned side by side;

[0036] Fig. 2 is an exploded perspective of part of a cassette;

[0037] Fig. 3 is a partial perspective view of an end of the cassette showing an air inlet or air outlet duct;

[0038] Fig. 4 is a schematic perspective view of the building showing two cassettes and including the air circulation system;

[0039] Fig. 5 is an exploded partial perspective view of a second cassette;

[0040] Fig. 6 is a partial perspective view of part of a building incorporating the present invention in the wall and floor; and

[0041] Figs 7A-7C are exploded perspective views of a floor, wall and roof panels respectively.

[0042] As described below, the cassette has a of the layer of concrete on a profiled steel deck. Both of these terms are intended to be interpreted broadly. There are many types of profiled steel deck which are known in the art (for example made by Tata steel under the Comflor (RTM) brand). These generally take the form of a flat sheet of steel which is rolled to provide a number of upstanding profiled features which typically have upstanding rectangular, trapezoidal or more complex shape. Any suitable profiled shape can be used in the present invention. The deck may be perforated to allow flow between adjacent profiles.

[0043] Similarly, the term “concrete” is intended to define any form of concrete including traditional concrete, and more modern types of “green concrete” including those to be developed.

[0044] The basic structure of the cassette is shown in Figs 1 -3. These comprise a profiled steel and deck 1 onto which a layer concrete 2 has been poured and been set. The profiled steel deck has a number of upstanding profiled portions 3. A flat sheet 4 is fixed for example by welding, mechanical fasteners, adhesive or a combination of these, to the lower face of the profiled steel deck 1 . The flat sheet 4 co-operates with the profile portions 3 to form a plurality of air passages 5 along the length of the cassette.

[0045] In its simplest form the sheet 4 is flat, but it could also be profiled provided that it can still form the air passages. The profiled steel deck 1 shown in Figs. 1 and 3 has smaller profiled portions 3A which are simply a feature of the profile selected for this example. These can either be blocked up of can form auxiliary air passages.

[0046] Extending downwardly from the sheet 4 is a suspension system 6 in the form of a beam 7 creating upper 8 and lower 9 channels. The beam is preferably formed of a single piece that is rolled into the E-shape configuration as shown in the drawings. At the junction between adjacent cassettes, two beams 7 are provided back-to-back as shown in Fig 1 . The beam 7 is attached to the flat sheet 4 by welding, mechanical fasteners, adhesive or a combination of these. In the vicinity of the beams, the sheet may be absent, and the beams can then be attached directly to the profiled steel deck 1 . However, it is simpler to have a continuous sheet 4 to which the beams are attached through both the flat sheet and the profiled sheet.

[0047] In practice, a slab of insulation can be fitted between adjacent upper channels 8. Lower channel 9 is provided with a plurality of openings 10. Services including wiring and ducting can be fitted into the lower channels 9 and can extend between adjacent channels via the openings 10. The concrete 2 and profiled steel deck 1 extend laterally beyond the suspension system 6. This allows the outermost edge of the profiled steel deck 1 to be supported on the framework of the building. The suspension system 6 is not a load bearing component, it is merely suspended from the lower face of the cassette. Further details of the suspension system and other features which can be incorporated into the cassette are disclosed in W02022 / 090076.

[0048] In order to supply the air passages 5 with air, an air inlet duct 20 is provided as shown in Fig 3. The duct 20 is formed from a metal or plastic sheet which has been bent or formed into the shape shown in Fig 3. This represents a simple way to provide the duct, but other solutions can be provided such as a part cylindrical duct with an open side which is attached to the cassette, or a closed tube with a number of side passages are attached to the individual air passages 5.

[0049] The illustrated duct 20 has a lower wall 21 which leads to a rear wall 22 which leads to a top wall 23 which leads to a front wall 24. As shown in Fig 3, the duct 20 is in a partially assembled state in which it has not been attached to the end of the cassette. From the position shown, it is moved to the left such that the lower wall 21 overlaps with the sheet 4 and is fixed to it by welding, mechanical fasteners, adhesive or a combination of these. In this position, the front face 24 abuts the concrete 2 above the air passages 5 and is fixed to to the concrete by mechanical fasteners and / or an adhesive.

[0050] At the far end of the air inlet duct 20 in Fig 3 there is an air inlet 25 sealed to the inlet duct 20 to allow air into the air inlet duct 20. The opposite end of the air inlet duct 20 is closed off by an end plate (not shown) thereby creating an air flow passage via the air inlet 25 along the air inlet duct 20 and out through the air passages 5.

[0051] Fig 3 can also be considered to illustrate the air outlet duct 30. This has the same structure as the air inlet duct 20 and is positioned at the opposite end of the cassette to receive air from the air passages 5 which is then discharged along air outlet 35.

[0052] The above described structure can be formed in situ in a generally conventional manner. In this case, the deck 1 with the flat sheet 4 already in place is installed as is well known in the art. Concrete 2 is then poured. Once set, the air inlet duct 20 and air outlet duct 30 are fixed in place and the remainder of the distribution system as described below is then connected up.

[0053] Alternatively, all of the above structure can be formed as a cassette in a factory and can include optional additional features including insulation and ducting / wiring for services. This cassette can be lifted into place on a building frame which support the cassette in place.

[0054] Fig 4 shows the manner in which the cassettes are incorporated into a building B and it also shows the air circulation system. Two cassettes are shown in Fig 4. These may either be a floor and ceiling cassette for a single floor, or floor cassettes for different floors.

[0055] Heating in this example is provided by solar thermal heating panels 40 which may, for example, be mounted on the roof of the building B or at some other convenient location. Depending on the size of the building B, there may be a number of solar wall panels 40 or a single solar wall panel 40 may be configured to provide hot air to a number of buildings.

[0056] The solar thermal heating panels 40 may be intermittently covered with solar photovoltaic panels 41 .The solar heating panels effectively act as a heat sink for the photovoltaic panels 41 allowing them to operate at a cooler temperature and hence generate more efficiently.. These can provide electrical power which can be stored or used externally of the heating system and possibly exported to the grid.

[0057] The solar thermal heating panels 40 are able to meet the heat demand of the building when the temperature differential between the building and panel is below a certain threshold. Above that threshold, part of the thermal demand can be met using an auxiliary heater powered by electrical energy produced by the photovoltaic panels. If these cannot provide sufficient power, external power may be required.

[0058] The solar thermal heating panels 40 could be any form of solar heating, for example, the Solarwall (RTM) produced CA Group. This is also known as a Trombe Wall and has been around for many decades.

[0059] Other forms of heating such as ground source hearing or an air compressor may be provided as well as or in addition to the solar heating to give additional capacity in the event that a solar heater is incapable of meeting demand for a given period. As shown in Fig 4, there are six solar thermal heating panels which are connected to hot air supply duct 42 such that air heated in the panels 40 is transported by the hot air supply duct 42 to a hot air manifold 43. From here, individual hot air pipes 44 lead to respective air inlets 25 of the air inlet ducts 20 so that the hot air passes along the air passages 25 to the respective air outlet duct 30.

[0060] From there, it is conveyed by air return pipes 45 to an air return (exhaust) manifold 46, to duct 47 which leads to the mechanical ventilation heat exchange which collects the heat from the air ducted from pipes 45, manifold 46 and duct 47, and then to the atmosphere. This air may either be exhausted to atmosphere via exhaust outlet 48 or be fed via the warm air return 46 to warm air exhaust via thermostatic return valve 53 which leads via hot air pipes 44 to respective warm air outlets 52 which discharge warm air to the underside of the floor and / or walls, in order to provide heat to the underside floor within the building.

[0061] The thermostatic valve 53 allows hot air to be diverted from the hot air exhaust supply duct 47 to the pipe 42 if desired. Alternatively, the warm air leaving the building can be used to heat the incoming air after it is heated by mvhe. (Mechanical Ventilation Heat Exchange)

[0062] The solar warmed air circulation system can readily be used with an existing mechanical ventilation and heat exchange (mvhe) system 54 which has an air inlet 55. The mvhe system can be used to draw air through the building and at least a portion of the incoming air flow can be diverted via the cassettes as described above before the air from the outlet ducts is fed to the mvhe to ventilate and possibly also further warm the building. This can be done by an optional thermostatic valve (not shown) provided to divert hot air from the hot air supply duct 42 to the hot air manifold 42 and then to the pipes 44 to heat the underside of the floor or walls, or roof. Alternatively or additionally the air circulation system can have a separate induction or impeller fan.

[0063] Fresh air to the mvhe is used for collecting the heat from the exhausted air having been extracted by a heat exchange plate. This fresh and now heated air is fed via heated fresh air duct 49, manifold 50 and pipes 51 into the rooms via the air outlet 52 in the ceiling.

[0064] An alternative cassette arrangement is shown in Fig 5 which is an exploded view of said cassette including one suspension system 6. In this case, the air passages 5 have a generally square cross-sectional shape and the cassette is provided with a sandwich sheet 60 which is fixed to the top of the air passages. This allows the gaps between the deck 1 and sandwich sheet 60 to be used as additional air passages. Concrete may then be poured on the top of the sandwich sheet 60. Alternatively, particularly if the cassette is used as a wall or ceiling panel, a concrete particle board may be installed on the sandwich sheet. For a wall cassette having this type of configuration, the preferred option is that cement particle board provides the flat sheet 4 and the sandwich sheet 60 is steel, onto which concrete is then poured. For a wall or roof / ceiling panel having this type of configuration, the preferred option is that the flat sheet 4 is a steel sheet and the sandwich sheet 60 is cement particle board.

[0065] Fig 6 shows a cassette as described above for the floor panel. This leads to the outlet duct 30. From there, a connecting pipe 70 leads to a wall 71 which is provided with a similar structure. By putting together various structures of this type and connecting the ducts together, the hot air can be transferred around the floors, walls and ceilings of the building. The mvhe provides the extraction of the solar warmed air which heats the underside of the floors, walls and roofs, thereby pulling the air through and generating the heat for the building.

[0066] Figs 7A-7C show floor, wall and roof panels respectively. These each comprise a profiled steel and deck 1 , a cementitious board 80 and a flat sheet 4. These are generally configured as described above except that the cementitious board 80 is used in place of the poured concrete 2. The floor panel has the suspension system 6 as previously described.

[0067] The profiled steel deck 1 has a trapezoidal cross section oriented in the opposite sense to the first example such that the air passages 5 are wider at the side closest to the flat sheet 4. Profiled portions 3 form ducts to convey air to and from the air passages 5. Additional profiled portions 81 can be provided either to convey air or to support other panels such as insulation. A distribution system similar to that shown in Fig 4 can distribute air to the different panels. This can be controlled by a valve system to meet the heating requirements of the building.

Claims

Claims:1 . A structural cassette comprising a profiled steel deck having a generally planar base layer from which a plurality of raised profiles extend on one side, the profiles extending for the full length of the cassette; a thermal storage layer on the one side of the profiled steel deck, a sheet fitted below the profiled steel deck to form a plurality of air passages between the sheet and the raised profiles; an air inlet duct at one end of the cassette in communication with the air passages; and an air outlet duct at the opposite end of the cassette in communication with the air passages.

2. A structural cassette according to claim 1 , wherein the profiled steel deck and thermal storage layer are a self-supporting structural component.

3. A structural cassette according to any of the preceding claims, wherein a non-load bearing element is attached beneath the sheet.

4. A structural cassette according to claim 3, wherein the non-load bearing component provides support for services and / or insulation.

5. A structural cassette according to claim 3, wherein the non-load bearing structure is a beam structure attached to the underside of the cassette in order to provide at least one joist on its lower face.

6. A structural cassette according to claim 5, wherein the beam structure is a separate structure fixed to the sheet.

7. A structural cassette according to claim 5 or claim 6, wherein each beam structure forms at least two channels.

8. A structural cassette according to any of claims 5 to 7, wherein the beam structure is provided with through holes.

9. A structural cassette according to any of the preceding claims wherein the thermal storage layer is a cementitious material.

10. A structural cassette according to any of claims 1-8 wherein the thermal storage layer is concrete.11 . A structural cassette according to any of the preceding claims wherein the thermal storage layer has a thermal storage capacity of greater than 600 J / kg°C, preferably greater than 700 J / kg°C and more preferably greater than 800 J / kg°C.

12. A structural cassette according to any of the preceding claims wherein the profiled steel deck has a trapezoidal profile in which the air passages are wider at the side closest to the sheet.

13. A structural cassette according to any of the preceding claims wherein the profiled steel deck is fixed to the sheet by chemical bonding, mechanical fixing, and / or spot welding.

14. A building comprising a framework which supports a plurality of floor, wall and / or ceiling / roof panels; at least one of the panels comprising: a structural cassette according to any of the preceding claims; an air circulation system for circulation of heated and / or cooled air to the inlet duct and from the outlet duct; and a heating and / or cooling unit to heat and / or cool air for the air circulation unit.

15. A building according to claim 12, wherein the air circulation system is provided with a heat recovery system from the air leaving at the air outlet duct.

16. A building according to claim 15 wherein the air circulation system comprises a thermostatically-operated valve to recycle air from the outlet duct back to the heating / cooling unit.

17. A building according to claim 15 or 16 wherein the air circulation system comprises a mechanical ventilation heat exchanger.

18. A building according to any of claims 14 to 17, wherein the air circulation system comprises a valve system and a control system to selectively circulate heated and / or cooled air to the floor, wall and / or ceiling / roof panels.

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